Light gas gun projectile

Abstract

An improved light gas gun launches a projectile in a light gas atmosphere as it travels through a frictionless barrel to achieve high muzzle velocities, decreased acoustic signatures, and increased ranges. The light gas atmosphere is introduced by a purge valve prior to firing or by a muzzle valve that holds a positive light gas pressure on the barrel and breech. The muzzle valve also routes the majority of propellant gases through a suppression canister, reducing the light gas gun's acoustic signature. The frictionless barrel uses light gas propellant routed through gas bearings to keep the projectile centered in the barrel and preclude the projectile from contacting the barrel walls, eliminating barrel wear. The system includes a projectile assembly that stores light gas from the firing and injects it into the boundary layer, reducing drag, increasing range and lethality, and decreasing acoustic signature of the projectile down range.

What I claim is: 
     
       1. A projectile assembly comprising:
 a projectile body generally ogive in shape at the forward end with a rounded nose and a boat tail shape toward the rear of the projectile;
 said projectile body is manufactured in two parts, the forward projectile body and the aft projectile body;
 said forward projectile body having a bore with a predetermined diameter extending a predetermined depth from a flat aft face, the bore being internally threaded; 
 said aft projectile body having a through-bore with a second predetermined diameter, the through-bore having a taper at the rear of said aft projectile body and the aft projectile body is threaded externally to allow said forward projectile body and aft projectile body to be screwed together; 
 said aft projectile body contains a spring loaded valve that seats in the taper at the aft end of said aft projectile body; 
 
 said spring loaded valve opens the projectile body to accept and store high pressure light gas internally when light gas pressure externally is greater than the gas pressure internal to said projectile body; 
 said spring loaded valve closes when external pressure drops below the pressure internal to said projectile assembly; 
 said projectile body comprised of sintered metal with appropriately coarse grains to allow light gas to flow through the walls of said projectile body, injecting light gas into a boundary layer surrounding said projectile assembly during flight, thereby reducing aerodynamic drag and ballistic disturbances as said projectile assembly travels downrange, which increases range and accuracy while decreasing acoustic signature of said projectile assembly as it travels through the atmosphere; 
 said projectile body having a forward center of gravity and rearward center of pressure to increase ballistic stability in flight through all flight regimes ranging from supersonic, transonic, to subsonic velocities.